In recent years, smart phones or tablet personal computers (PCs) have actively propagated, and the technology for electronic apparatuses mounted with a contact position measuring device has been actively developed. The smart phones or the tablet PCs may typically include touch screens, and the user may designate a specific position of the touch screen using a stylus pen. A specific signal may be input to a smart phone by designating the specific position of the touch screen by the user.
The current touch screens may perform various functions according to a position of the stylus pen and writing pressure in the position of the stylus pen by detecting the position and writing pressure of the stylus pen. To detect the writing pressure of the stylus pen, a variable capacitor of which capacitance is varied according to the writing pressure of the stylus pen may be provided in the stylus pen.
The capacitance of the variable capacitor may be varied according to a distance between two electrodes or an area between two electrodes. The variable capacitor of which the capacitance is changed by the variation in the area between two electrodes may be typically employed in the stylus pen.
It is difficult to couple an electrode disposed close to a front end of the stylus pen employing the variable capacitor to a resonance circuit in that two electrodes of the capacitor have to be arranged in a longitudinal direction of the stylus pen and the resonance circuit is arranged in a rear end of the stylus pen.
There is a need for a technology for coupling both of two electrodes to the resonance circuit without a change in a diameter of the stylus pen in that the current stylus pen has to be implemented to have a diameter as small as possible.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.